Stand height concerns

Howdy all, my 150 gal has been ordered and I am building my stand this weekend. I am planning on getting a 55gal for the sump and I only recently realized that this stand will have to be pretty darn tall in order for me to be able to do sump maintenance.

So I guess my question is, for those of you with sumps, is how much vertical space do I really need between top of sump and under side of stand to be able to work on it in a practical manner?

I don't have a problem making a 42" or more stand, but at only 18" wide for the tank, i'm concerned about tipping issues with a whole system that will 6 feet tall or so. Any thoughts?

Plan on 21" tall, 55 gal sump, stand with 2x4's...if I want 20" of space to work on sump, my stand will end up being 49"....seems a bit high. What is the least amount of space I will really need? If I take stand down to 42", that only leaves me with 13" of clearance between too of sump and under side of stand...will this be enough? Thanks all!

This would put top of tank at 72" btw with center of tank at 57", I think I can live with that...42" tall by 22" wide. With braces on wall for peace of mind (great suggestion btw, ty). Will definitely be using a step ladder for cleaning, but oh well...

dont know how I will reach the bottom of the overflow boxes for cleaning lol.. Figure that out later